From b234fca7ddbdbeaca2b88cce137d9231bcce01b4 Mon Sep 17 00:00:00 2001
From: ethan <zhufeng_solo@163.com>
Date: Sat, 23 Mar 2024 18:45:05 +0800
Subject: [PATCH] To incorporate double-arrow animation.

---
 debug/index.ts            |   7 ++
 index.html                |   1 +
 src/arrow/double-arrow.ts |  54 ++++++++++--
 src/base.ts               | 175 +++++++++++++++++++++++++++++++++++++-
 src/interface.ts          |  14 ++-
 5 files changed, 240 insertions(+), 11 deletions(-)

diff --git a/debug/index.ts b/debug/index.ts
index 6cb9433..24a3f54 100644
--- a/debug/index.ts
+++ b/debug/index.ts
@@ -47,6 +47,7 @@ const editStartHandler = () => {
 const editEndHandler = (geometryPoints: any) => {
   console.error('editEnd', geometryPoints);
 };
+
 const buttonGroup = document.getElementById('button-group') as HTMLElement;
 buttonGroup.onclick = (evt) => {
   const targetElement = evt.target as HTMLElement;
@@ -160,6 +161,12 @@ buttonGroup.onclick = (evt) => {
         geometry.off('editEnd', editEndHandler);
       }
       break;
+
+    case 'startGrowthAnimation':
+      if (geometry) {
+        geometry.startGrowthAnimation();
+      }
+      break;
     default:
       break;
   }
diff --git a/index.html b/index.html
index db3caff..81e4d85 100644
--- a/index.html
+++ b/index.html
@@ -68,6 +68,7 @@
       <button id="remove">删除</button>
       <button id="addEvent">绑定事件</button>
       <button id="removeEvent">解绑事件</button>
+      <button id="startGrowthAnimation">生长动画</button>
     </div>
     <script>
       window.CESIUM_BASE_URL = 'node_modules/cesium/Build/Cesium';
diff --git a/src/arrow/double-arrow.ts b/src/arrow/double-arrow.ts
index dc1cd4c..ccefb63 100644
--- a/src/arrow/double-arrow.ts
+++ b/src/arrow/double-arrow.ts
@@ -15,6 +15,12 @@ export default class DoubleArrow extends Base {
   neckHeightFactor: number;
   connPoint: Position;
   tempPoint4: Position;
+  minPointsForShape: number;
+  llBodyPnts: Position[] = [];
+  rrBodyPnts: Position[] = [];
+  curveControlPointLeft: Cartesian3;
+  curveControlPointRight: Cartesian3;
+  isClockWise: boolean;
 
   constructor(cesium: any, viewer: any, style?: PolygonStyle) {
     super(cesium, viewer, style);
@@ -25,6 +31,7 @@ export default class DoubleArrow extends Base {
     this.neckWidthFactor = 0.15;
     this.connPoint = [0, 0];
     this.tempPoint4 = [0, 0];
+    this.minPointsForShape = 4;
     this.setState('drawing');
   }
 
@@ -42,8 +49,30 @@ export default class DoubleArrow extends Base {
     } else if (this.points.length === 2) {
       this.setGeometryPoints(this.points);
       this.drawPolygon();
-    } else if (this.points.length === 4) {
+    } else if (this.points.length === 3) {
+      this.lineEntity && this.viewer.entities.remove(this.lineEntity);
+    } else {
       this.finishDrawing();
+      this.curveControlPointLeft = this.cesium.Cartesian3.fromDegrees(this.llBodyPnts[2][0], this.llBodyPnts[2][1]);
+      this.curveControlPointRight = this.cesium.Cartesian3.fromDegrees(this.rrBodyPnts[1][0], this.rrBodyPnts[1][1]);
+
+      // 辅助查看插值控制点位置
+      // this.CesiumViewer.entities.add({
+      // 	position: this.curveControlPointLeft,
+      // 	point: {
+      // 		pixelSize: 10,
+      // 		heightReference: this.cesium.HeightReference.CLAMP_TO_GROUND,
+      // 		color: this.cesium.Color.RED,
+      // 	},
+      // });
+      // this.CesiumViewer.entities.add({
+      // 	position: this.curveControlPointRight,
+      // 	point: {
+      // 		pixelSize: 10,
+      // 		heightReference: this.cesium.HeightReference.CLAMP_TO_GROUND,
+      // 		color: this.cesium.Color.RED,
+      // 	},
+      // });
     }
   }
   /**
@@ -55,7 +84,7 @@ export default class DoubleArrow extends Base {
     if (tempPoints.length === 2) {
       this.addFirstLineOfTheArrow();
     } else if (tempPoints.length > 2) {
-      const geometryPoints = this.createPolygon(tempPoints);
+      const geometryPoints = this.createGraphic(tempPoints);
       this.setGeometryPoints(geometryPoints);
       this.drawPolygon();
     }
@@ -66,7 +95,7 @@ export default class DoubleArrow extends Base {
    */
   updateDraggingPoint(cartesian: Cartesian3, index: number) {
     this.points[index] = cartesian;
-    const geometryPoints = this.createPolygon(this.points);
+    const geometryPoints = this.createGraphic(this.points);
     this.setGeometryPoints(geometryPoints);
     this.drawPolygon();
   }
@@ -74,7 +103,7 @@ export default class DoubleArrow extends Base {
   /**
    * Generate geometric shapes based on key points.
    */
-  createPolygon(positions: Cartesian3[]) {
+  createGraphic(positions: Cartesian3[]) {
     const lnglatPoints = positions.map((pnt) => {
       return this.cartesianToLnglat(pnt);
     });
@@ -92,7 +121,8 @@ export default class DoubleArrow extends Base {
     }
     let leftArrowPnts: Position[];
     let rightArrowPnts;
-    if (Utils.isClockWise(pnt1, pnt2, pnt3)) {
+    this.isClockWise = Utils.isClockWise(pnt1, pnt2, pnt3);
+    if (this.isClockWise) {
       leftArrowPnts = this.getArrowPoints(pnt1, this.connPoint, this.tempPoint4, false);
       rightArrowPnts = this.getArrowPoints(this.connPoint, pnt2, pnt3, true);
     } else {
@@ -104,9 +134,11 @@ export default class DoubleArrow extends Base {
     const llBodyPnts = leftArrowPnts.slice(0, t);
     const lArrowPnts = leftArrowPnts.slice(t, t + 5);
     let lrBodyPnts = leftArrowPnts.slice(t + 5, m);
+    this.llBodyPnts = llBodyPnts;
     let rlBodyPnts = rightArrowPnts.slice(0, t);
     const rArrowPnts = rightArrowPnts.slice(t, t + 5);
     const rrBodyPnts = rightArrowPnts.slice(t + 5, m);
+    this.rrBodyPnts = rrBodyPnts;
     rlBodyPnts = Utils.getBezierPoints(rlBodyPnts);
     const bodyPnts = Utils.getBezierPoints(rrBodyPnts.concat(llBodyPnts.slice(1)));
     lrBodyPnts = Utils.getBezierPoints(lrBodyPnts);
@@ -220,4 +252,16 @@ export default class DoubleArrow extends Base {
   getPoints() {
     return this.points;
   }
+
+  getBezierControlPointforGrowthAnimation() {
+    return this.isClockWise
+      ? {
+          left: this.curveControlPointLeft,
+          right: this.curveControlPointRight,
+        }
+      : {
+          right: this.curveControlPointLeft,
+          left: this.curveControlPointRight,
+        };
+  }
 }
diff --git a/src/base.ts b/src/base.ts
index 9b03a41..6827bd6 100644
--- a/src/base.ts
+++ b/src/base.ts
@@ -1,5 +1,4 @@
 // @ts-ignore
-// import * as CesiumTypeOnly from 'cesium';
 import * as CesiumTypeOnly from 'cesium';
 import {
   State,
@@ -9,10 +8,12 @@ import {
   EventType,
   EventListener,
   VisibleAnimationOpts,
+  GrowthAnimationOpts,
 } from './interface';
 import EventDispatcher from './events';
 import cloneDeep from 'lodash.clonedeep';
-import merge from 'lodash.merge';
+// import merge from 'lodash.merge';
+import * as Utils from './utils';
 
 export default class Base {
   cesium: typeof CesiumTypeOnly;
@@ -34,6 +35,7 @@ export default class Base {
   points: CesiumTypeOnly.Cartesian3[] = [];
   isHidden: boolean = false;
   styleCache: GeometryStyle | undefined;
+  minPointsForShape: number = 0;
 
   constructor(cesium: CesiumTypeOnly, viewer: CesiumTypeOnly.Viewer, style?: GeometryStyle) {
     this.cesium = cesium;
@@ -642,6 +644,170 @@ export default class Base {
     }, delay);
   }
 
+  startGrowthAnimation(opts: GrowthAnimationOpts) {
+    const { duration = 3000, delay = 0, callback } = opts || {};
+    if (this.state !== 'static') {
+      return;
+    }
+    if (!this.minPointsForShape) {
+      console.warn('Growth animation is not supported for this type of shape');
+      return;
+    }
+    this.setState('animating');
+    if (this.minPointsForShape === 4) {
+      // For double arrows, special handling is required.
+      this.doubleArrowGrowthAnimation(duration, delay, callback);
+      return;
+    }
+    setTimeout(() => {
+      this.hideWithAnimation(0, 0, undefined);
+      const points = this.getPoints();
+
+      let segmentDuration = 0;
+      if (this.minPointsForShape === 2) {
+        segmentDuration = duration / (points.length - 1);
+      } else {
+        segmentDuration = duration / (points.length - 2);
+      }
+
+      let startTime = Date.now();
+      let movingPointIndex = 0;
+      this.viewer.clock.shouldAnimate = true;
+
+      const frameListener = (clock) => {
+        const currentTime = Date.now();
+        const elapsedTime = currentTime - startTime;
+        if (elapsedTime >= duration) {
+          // Animation ends
+          callback && callback();
+          startTime = 0;
+          this.viewer.clock.shouldAnimate = false;
+          this.viewer.clock.onTick.removeEventListener(frameListener);
+          this.setState('static');
+          return;
+        }
+
+        const currentSegment = Math.floor(elapsedTime / segmentDuration);
+        let startPoint;
+
+        if (this.minPointsForShape === 2) {
+          movingPointIndex = currentSegment + 1;
+        } else {
+          movingPointIndex = currentSegment + 2;
+        }
+        startPoint = points[movingPointIndex - 1];
+        if (currentSegment == 0 && this.minPointsForShape === 3) {
+          // The face-arrow determined by three points, with the animation starting from the midpoint of the line connecting the first two points.
+          startPoint = this.cesium.Cartesian3.midpoint(points[0], points[1], new this.cesium.Cartesian3());
+        }
+        let endPoint = points[movingPointIndex];
+        // To dynamically add points between the startPoint and endPoint, consistent with the initial drawing logic,
+        // update the point at index movingPointIndex in the points array with the newPosition, 
+        // generate the arrow, and execute the animation.
+        const t = (elapsedTime - currentSegment * segmentDuration) / segmentDuration;
+        const newPosition = this.cesium.Cartesian3.lerp(startPoint, endPoint, t, new this.cesium.Cartesian3());
+        const tempPoints = points.slice(0, movingPointIndex + 1);
+        tempPoints[tempPoints.length - 1] = newPosition;
+        const geometryPoints = this.createGraphic(tempPoints);
+        this.setGeometryPoints(geometryPoints);
+        this.showAnimation(0, 0, undefined);
+      };
+      this.viewer.clock.onTick.addEventListener(frameListener);
+    }, delay);
+  }
+
+  private doubleArrowGrowthAnimation(duration: number = 3000, delay: number = 0, callback?: Function) {
+    setTimeout(() => {
+      this.viewer.entities.remove(this.polygonEntity);
+      this.viewer.entities.remove(this.outlineEntity);
+      this.polygonEntity = null;
+      this.outlineEntity = null;
+      const points = this.getPoints();
+      let startTime = Date.now();
+      this.viewer.clock.shouldAnimate = true;
+
+      const frameListener = (clock) => {
+        const currentTime = Date.now();
+        const elapsedTime = currentTime - startTime;
+        if (elapsedTime >= duration) {
+          // Animation ends
+          callback && callback();
+          startTime = 0;
+          this.viewer.clock.shouldAnimate = false;
+          this.viewer.clock.onTick.removeEventListener(frameListener);
+          this.setState('static');
+          return;
+        }
+
+        // Utils.isClockWise(pnt1, pnt2, pnt3)
+        const midPoint = this.cesium.Cartesian3.midpoint(points[0], points[1], new this.cesium.Cartesian3());
+
+        const startPointLeft = this.cesium.Cartesian3.midpoint(points[0], midPoint, new this.cesium.Cartesian3());
+
+        const startPointRight = this.cesium.Cartesian3.midpoint(midPoint, points[1], new this.cesium.Cartesian3());
+        let endPointLeft = points[3];
+        let endPointRight = points[2];
+        const t = elapsedTime / duration;
+        const controlPoint = this.getBezierControlPointforGrowthAnimation();
+        let curveControlPointsLeft = [startPointLeft, controlPoint.left, endPointLeft];
+        let curveControlPointsRight = [startPointRight, controlPoint.right, endPointRight];
+        const newPositionLeft = this.getNewPosition(curveControlPointsLeft, t);
+        const newPositionRight = this.getNewPosition(curveControlPointsRight, t);
+
+        // Assist in viewing exercise routes
+        // this.viewer.entities.add({
+        // 	position: newPositionLeft,
+        // 	point: {
+        // 		pixelSize: 4,
+        // 		heightReference: this.cesium.HeightReference.CLAMP_TO_GROUND,
+        // 		color: this.cesium.Color.RED,
+        // 	},
+        // });
+        // this.viewer.entities.add({
+        // 	position: newPositionRight,
+        // 	point: {
+        // 		pixelSize: 4,
+        // 		heightReference: this.cesium.HeightReference.CLAMP_TO_GROUND,
+        // 		color: this.cesium.Color.RED,
+        // 	},
+        // });
+        const tempPoints = [...points];
+        tempPoints[2] = newPositionRight;
+        tempPoints[3] = newPositionLeft;
+        const geometryPoints = this.createGraphic(tempPoints);
+        this.setGeometryPoints(geometryPoints);
+        this.drawPolygon();
+      };
+      this.viewer.clock.onTick.addEventListener(frameListener);
+    }, delay);
+  }
+
+  private getNewPosition(curveControlPoints, t) {
+    curveControlPoints = curveControlPoints.map((item) => {
+      return this.cartesianToLnglat(item);
+    });
+    let curvePoints = Utils.getCurvePoints(0.3, curveControlPoints);
+    curvePoints = curvePoints.map((p) => {
+      return this.cesium.Cartesian3.fromDegrees(p[0], p[1]);
+    });
+
+    let newPosition = this.interpolateAlongCurve(curvePoints, t);
+    return newPosition;
+  }
+
+  private interpolateAlongCurve(curvePoints, t) {
+    const numPoints = curvePoints.length - 1;
+    const index = Math.floor(t * numPoints);
+    const tSegment = t * numPoints - index;
+    const startPoint = curvePoints[index];
+    const endPoint = curvePoints[index + 1];
+    const x = startPoint.x + (endPoint.x - startPoint.x) * tSegment;
+    const y = startPoint.y + (endPoint.y - startPoint.y) * tSegment;
+    const z = startPoint.z + (endPoint.z - startPoint.z) * tSegment;
+
+    return new this.cesium.Cartesian3(x, y, z);
+  }
+
   remove() {
     if (this.type === 'polygon') {
       this.viewer.entities.remove(this.polygonEntity);
@@ -692,4 +858,9 @@ export default class Base {
     return 'polygon';
     //Abstract method that must be implemented by subclasses.
   }
+
+  createGraphic(points: CesiumTypeOnly.Cartesian3[]): CesiumTypeOnly.Cartesian3[] {
+    //Abstract method that must be implemented by subclasses.
+    return [new this.cesium.Cartesian3()];
+  }
 }
diff --git a/src/interface.ts b/src/interface.ts
index a7b93f2..974c5c9 100644
--- a/src/interface.ts
+++ b/src/interface.ts
@@ -12,14 +12,20 @@ export type LineStyle = {
   lineWidth?: number;
 };
 
-export type State = 'drawing' | 'edit' | 'static';
+export type State = 'drawing' | 'edit' | 'static' | 'animating';
 export type GeometryStyle = PolygonStyle | LineStyle;
 
 export type EventType = 'drawStart' | 'drawUpdate' | 'drawEnd' | 'editEnd' | 'editStart';
 export type EventListener = (eventData?: any) => void;
 
-export type VisibleOpts = {
+export type VisibleAnimationOpts = {
   duration?: number;
   delay?: number;
-  callback?: (() => void)
-}
+  callback?: () => void;
+};
+
+export type GrowthAnimationOpts = {
+  duration: number;
+  delay: number;
+  callback: Function;
+};